What Is an Aneurysm?

Medically Reviewed by James Beckerman, MD, FACC on May 06, 2021

If you get an aneurysm, it means you have a bulge in the wall of an artery. It happens when the pressure of blood passing through has forced a weakened part of the artery to balloon outward or when the blood vessel wall is weakened for a different reason.

Aneurysms can happen in any blood vessel, but they usually form in the belly or chest portions of your aorta -- the main blood vessel that carries blood from your heart -- or in arteries that nourish your brain.

Aneurysms there are serious, while those in other areas, such as your leg, can be less hazardous.

The most serious threat of an aneurysm is that it will burst and cause a stroke or massive bleeding, which can be life-threatening. A large aneurysm can affect your circulation and lead to blood clots.

It's important to get it diagnosed and treated early. Aneurysms often have mild symptoms or none at all, so routine exams can help your doctor check for warning signs.

aortic aneurysm


Types of Aneurysms

Aortic aneurysm. As the name suggests, this type happens in your aorta. It can be linked with hardening of the arteries, also known as atherosclerosis. It may be an inherited condition or a complication of high blood pressure or smoking.

Cerebral aneurysm. Also known as a berry aneurysm, you get this kind in the wall of a blood vessel in your brainSmoking raises your risk of getting one.

Popliteal artery. One of the more common peripheral vascular aneurysms, it is a bulging or weakness in the wall of the artery that supplies blood to the knee joint, calf and thigh. 

Ventricular aneurysm. This is a bulge in the wall of your heart. A previous heart attack is the most common cause. In rare cases, a severe chest injury can also lead to it.

What Causes an Aneurysm?

Any condition that causes your artery walls to weaken can bring one on. The most common culprits are atherosclerosis and high blood pressure.

Deep wounds and infections can also lead to an aneurysm. Or you may be born with weakness in one of your artery walls.